WASHINGTON - Republican presidential candidate Donald Trump called Monday for "foreign policy realism," focused on the destruction of Islamic State militants and other extremist groups, rather than reshaping nations to an American ideal.
Trump, in a foreign policy speech in the Midwestern battleground state of Ohio, said the United States needs to align itself with any country, regardless of past disputes, that wants to defeat "radical Islamic terrorism."
"We cannot let this evil continue," Trump said.
He said the rise of Islamic State is "the direct result" of foreign affairs policies advocated by President Barack Obama and his first-term secretary of state, Hillary Clinton, Trump's Democratic presidential opponent in the November 8 election.
"Hillary Clinton's disastrous policies launched Islamic State onto the world stage," he said. Trump also said that Clinton, seeking to become the first female U.S. president, "lacks the mental and physical stamina" to take on the jihadists.
If elected, Trump said he would call an international conference of world leaders to devise a new plan to "crush and destroy" Islamic terrorism. He said the "era of nation-building" for the U.S. "will come to a swift and decisive end."
Trump's plans targeting Islamic State jihadists in the Middle East came just days after he falsely claimed that Obama and Clinton founded Islamic State. That assertion prompted a new round of criticism of his candidacy, yet Trump repeated the claim the following day before saying he meant the comment as sarcasm.
Trump, a real estate tycoon seeking his first elected office, also outlined other foreign policies he would adopt if he wins the election. Trump spelled out plans to revamp U.S. immigration policy to stop issuing visas to people seeking to enter the country if they cannot be adequately screened ahead of time.
Trump called it "extreme vetting." He said, "We will be tough. We will even be extreme."
The screening plan is a revision of Trump's original call to keep Muslims from entering the country until they could be vetted to insure they were not intent on launching a terrorist attack in the U.S. Trump called for temporarily suspending visas to people coming from geographic regions with a history of exporting terrorism, rather than by identifying the immigrants by their religion.
Trump, a one-time television reality show host, also said he wants to impose a new ideological test for admission into the United States, asking migrants looking to settle in the country for their views on religious freedom, gender equality, gay rights and other issues, to see whether they support American views on tolerance and ethnic pluralism.
Trump's call for a declaration that the United States is in ideological conflict with radical Islam is at odds with Obama's reluctance to single out the Islam faith itself as the root of worldwide terrorism. Clinton has long vowed to fight jihadists and says she is not opposed to saying "radical" Islam.
"From my perspective, it matters what we do more than what we say," Clinton said earlier this year. "Whether you call it radical jihadism or radical Islamism, I'm happy to say either. I think they mean the same thing."
Clinton campaigned Monday in Scranton, Pennsylvania, appearing alongside Vice President Joe Biden in the working-class city where he was born.
WATCH: Hillary Clinton on her view of America
She mocked Trump's national security and military credentials.
"I know he said he knows more than the generals," Clinton said. "No Donald, you don't. Donald Trump is temperamentally unfit to be president of the United States and totally unqualified."
Biden argued that Clinton understands the economic challenges middle-class families are facing, finding good jobs in the face of the country's declining manufacturing base of employment.
"She gets it," Biden said, "...and there's only one person in this election who will possibly help and that's Hillary Clinton."
The vice president also contended that "no major party nominee in the history of the United States has known less or been less prepared to deal with our national security than Donald Trump. And what bothers me, he doesn't seem to want to learn."
WATCH: Joe Biden on Trump's unpreparedness to deal with a nuclear attack
Clinton has moved to roughly a seven-percentage-point advantage over Trump in national political surveys and also holds leads in several battleground election states where the outcome of the national contest is likely to be decided. One new poll Monday also showed Clinton trouncing Trump in New York, the long-time Democratic stronghold where both candidates live, by a 57 percent to 27 percent margin.
In a series of comments Sunday on his Twitter account, Trump blamed the news media for his standing in the race against Clinton.
"If the disgusting and corrupt media covered me honestly and did not put false meaning into the words I say, I would be beating Hillary by 20 percent," Trump said.
In another, he said, "My rallies are not covered properly by the media. They never discuss the real message and never show crowd size or enthusiasm."
Numerous former Republican officials, most of whom served in some capacity during the administrations of former President George H.W. Bush and his son, President George W. Bush, the last two Republican presidents, have said in recent days they could not support Trump's candidacy. They have often said that he is ill-prepared to lead the country or does not have the appropriate temperament.
But in yet another tweet Monday, Trump said, "I have always been the same person — remain true to self. The media wants me to change but it would be very dishonest to supporters to do so!"
With Trump's weak showing in political polling, Republican officials in Washington are contemplating whether to drop their financial support for him and instead focus their efforts on Republican candidates running for Senate and House seats in Congress. Trump says he will stop raising money for the national party if it withdraws support from him.